I can't say that I've followed the debates of the Rio+20 conference, however two items in the news struck me as emblematic.
The first is the price-gouging by the hotels which hired out rooms to the attendees. Apparently the Brazilian government designated a travel agency to organise the large number of hotel rooms required. The agency saw a golden opportunity to make a fast buck and promptly set the price at $600 a night, with the result that large numbers of journalists and delegates who had planned to come stayed away. This of course makes no difference to the total ineffectiveness of such conferences, but it shows what capitalism really thinks of them.
The other, was a small item about one of the speakers being obliged to get her stand-in to deliver her speech... because she was stuck for several hours in Rio's traffic.